title: Statistical shape analysis of clavicular cortical bone with applications to the development of mean and boundary shape models.
abstract: During car collisions, the shoulder belt exposes the occupant's clavicle to large loading conditions which often leads to a bone fracture. To better understand the geometric variability of clavicular cortical bone which may influence its injury tolerance, twenty human clavicles were evaluated using statistical shape analysis. The interior and exterior clavicular cortical bone surfaces were reconstructed from CT-scan images. Registration between one selected template and the remaining 19 clavicle models was conducted to remove translation and rotation differences. The correspondences of landmarks between the models were then established using coordinates and surface normals. Three registration methods were compared: the LM-ICP method; the global method; and the SHREC method. The LM-ICP registration method showed better performance than the global and SHREC registration methods, in terms of compactness, generalization, and specificity. The first four principal components obtained by using the LM-ICP registration method account for 61% and 67% of the overall anatomical variation for the exterior and interior cortical bone shapes, respectively. The length was found to be the most significant variation mode of the human clavicle. The mean and two boundary shape models were created using the four most significant principal components to investigate the size and shape variation of clavicular cortical bone. In the future, boundary shape models could be used to develop probabilistic finite element models which may help to better understand the variability in biomechanical responses and injuries to the clavicle.
authors.affiliation: Virginia Tech and Wake Forest University, School of Biomedical Engineering and Sciences, Blacksburg, VA, USA.
authors.forename: Yuan-Chiao
authors.initials: YC
authors.lastname: Lu
authors.forename: Costin D
authors.initials: CD
authors.lastname: Untaroiu
mesh_terms: D002968:Clavicle / Q000033:anatomy & histology*; D006801:Humans; D008953:Models, Anatomic; D025341:Principal Component Analysis
keywords: 2D; 3D; ATD; CDS; CPU; CT; Clavicle; DetCov; FE; FOE; GPA; ICP; LM-ICP; Levenberg–Marquardt iterative closest point; MDL; MSS; Mean and boundary models; Model registration; NASS; PCA; PMHS; SD; SHREC; SLIDE; SPHARM; SPHARM registration with ICP; SSA; Statistical shape analysis; anthropomorphic test dummy; central processing unit; computed tomography; crashworthiness data system; determinant of the covariance matrix; finite element; first order ellipsoid; generalized procrustes alignment; iterative closest point; iterative landmark sliding; manually initialized subdivision surfaces; minimum description length; national automotive sampling system; post mortem human subject; principal component analysis; spherical harmonics; standard deviation; statistical shape analysis; three-dimensional; two-dimensional